JP2005106654A - Automatic inspection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic inspection system capable of inspecting accurately the size and the shape of a defect by scanning automatically from the most sensitive direction to the defect by a simple operation. <P>SOLUTION: In this automatic inspection system, a probe 10 is integrated with a scanning mechanism 20, and an inspection object 1 is automatically scanned, and a signal from the probe 10 is processed by an inspection data recording part 30, to thereby acquire inspection data. In the system, the inspection data acquired by scanning by the probe 10 are stored in an inspection data recording device 35 together with inspection data acquired by scanning beforehand, and the past inspection data are read and a control condition for next scanning is determined by a scanning control data generation part 40, and the condition is supplied to a scanning mechanism control device 50. In this case, automatic scanning is performed from the most sensitive direction to the defect 3, and the sensitivity to automatic defect detection is heightened, and the size and the shape of the defect can be inspected accurately. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic inspection system using an ultrasonic flaw detection technique, and more particularly to an automatic inspection system suitable for performing flaw detection in a place where a person cannot easily approach such as equipment of a nuclear power plant.

  Ultrasonic flaw detectors are a type of method for nondestructive inspection of defects inside an object, and have been widely used in the past. At this time, flaw detection is performed by automatically scanning a probe such as a probe. Several apparatuses have been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

  Here, Patent Document 1 relates to an invention entitled “Trackless Ultrasonic Flaw Detection Traveling Device”, Patent Document 2 relates to an invention entitled “Ultrasonic Flaw Detection Method Using a Robot”, and Patent Document 3 refers to “Automatic Ultrasonic of a Welded Portion”. Each of the inventions entitled “Flaw Detection Method and Apparatus” is disclosed.

  These devices and methods scan using a predetermined probe, and the scanning trajectory is determined in advance, such as a linear scan or a rectangular scan in a direction along the weld line or in a direction perpendicular to the weld line. Automatic flaw detection is performed according to the trajectory.

  In addition, at this time, several devices have been proposed in the past for devices that have been devised for accurately detecting the type and size of defects to be detected (see, for example, Patent Document 4 and Patent Document 5). .).

  Here, Patent Document 4 discloses an invention entitled “Sector Scanning Ultrasonic Inspection Apparatus”, and Patent Document 5 discloses an invention entitled “Ultrasonic Flaw Detection Apparatus”, which includes an array probe. It has been devised so that the S / N of the echo (reflected wave) signal from the defect end can be improved as much as possible by electronically fan-scanning or changing the scanning angle in the direction of the defect cross section. It is what.

  A method has also been proposed in which a probe can be moved along the surface of an object even when the inspection object has a complicated shape (see, for example, Patent Document 6).

Here, this Patent Document 6 discloses an invention entitled “Automatic Defect Evaluation Method for Centrifugal Impeller”, which includes a predetermined shape even if the object to be inspected has a complicated shape. An invention is disclosed in which automatic scanning can be performed along the line.
Japanese Patent Laid-Open No. 5-133842 Japanese Patent Laid-Open No. 11-14610 JP 2003-57215 A Japanese Patent Laid-Open No. 11-118777 Japanese Patent Laid-Open No. 11-248690 JP 9-325136 A

  The above prior art cannot be said to be considered for improving the S / N of the echo signal, and has a problem in improving the defect detection accuracy and operability.

  The automatic scanning of the probe (ultrasonic probe) according to the above-mentioned prior art is limited to a predetermined trajectory, and the ultrasonic wave is irradiated from the direction most sensitive to the assumed defect. I couldn't.

  Here, the most sensitive direction is generally the direction that is perpendicular to a defect such as a crack, but at this time, if there is a slight deviation from the direction with the best sensitivity, the main reflected wave is detected by the probe. It will not return in a certain direction, and only the scattered reflection component will return.

  Therefore, in order to irradiate ultrasonic waves from the most sensitive direction, the direction of the defect must be known in advance, but here the defect is originally irregular and its direction is also indefinite. It cannot be specified.

  Therefore, the scattered reflection component can only be detected in the prior art. However, since this scattered reflection component is generally weak, the S / N is lowered. Therefore, in the prior art, there is a problem in improving the defect detection accuracy. is there.

  Here, as described above, there is also known a prior art in which the S / N of the echo signal from the defect end is improved as much as possible, but these are also sensitive to defects. The probe is not scanned from the right direction.

  Further, in the conventional technique in which the probe can be moved along the surface of the object, it is necessary to register shape data for the object in advance and perform automatic flaw detection by performing a predetermined positioning setting.

  For this reason, for example, it is not possible to bring an inspection device into plant equipment and set it easily in a short time, or to easily perform automatic flaw detection without registering shape data for various shapes of inspection objects. There was a problem in improving operability.

  An object of the present invention is to provide an automatic inspection system that can automatically inspect the size and shape of a defect with high accuracy by automatically scanning the defect from the most sensitive direction with a simple operation.

  The first means for achieving the above object comprises means for automatically scanning an inspection object with an inspection probe combined with a scanning mechanism and processing the signal from the probe to detect the presence or absence of a defect, In the automatic inspection system for acquiring inspection data by the means, means for storing inspection data obtained by scanning with the inspection probe together with inspection data obtained by scanning before is provided, and inspection is performed by the inspection probe. When the object is automatically scanned, the past inspection data is read, and the inspection conditions for the next scanning are automatically changed. At this time, in the second means, the inspection probe has directivity, and at least one of the scanning mechanism and the inspection probe has means for changing the directivity direction.

  At this time, according to the third means, at least one of the scanning mechanism and the inspection probe itself is provided with means for changing the characteristics of the inspection probe.

  Also, at this time, according to the fourth means, the inspection probe is constituted by an array type probe in which detection elements are two-dimensionally arranged.

  Furthermore, at this time, according to the fifth means, the means for detecting the presence / absence of the defect is obtained by scanning the inspection object with the data when the healthy inspection object is actually scanned in advance under the same conditions. And at least one of the data based on the simulation result, and the presence or absence of a defect is detected based on the degree of coincidence.

  Furthermore, at this time, according to the sixth means, a defect model estimated from inspection data acquired in advance is incorporated into a model for performing a simulation when a healthy inspection object is scanned under the same conditions, A means for comparing the data obtained by performing simulation with the data obtained by scanning the inspection object and determining whether or not the state of the defect has been sufficiently clarified by the degree of coincidence. It is.

  Next, a seventh means for achieving the above object is a means for automatically scanning an inspection object using an inspection probe combined with a scanning mechanism and processing the signal from the probe to detect the presence or absence of a defect. In the automatic inspection system for obtaining inspection data by the means, shape measuring means for measuring the shape of the inspection object and generating shape data, and scanning for the automatic scanning based on the shape data Means for automatically generating control data.

  At this time, according to the eighth means, means for adding a mark to the surface of the inspection object is provided.

  As a result of the above, in the first means, first, in the automatic inspection system that attaches the probe to the scanning mechanism, automatically scans the inspection object, processes the signal from the probe and acquires the inspection data, A means for processing the signal to detect the presence or absence of a defect and a means for automatically changing the next inspection condition so that the state of the defect becomes clearer from the inspection data acquired before the defect is detected. Therefore, if all the inspection conditions are carried out to the end under the predetermined inspection conditions prepared until the means for detecting the presence or absence of defects by processing the signal from the probe detects the defects, the inspection object is defective. The test result is “None”.

  On the other hand, when the means for processing the signal from the probe to detect the presence or absence of a defect detects a defect, the inspection condition to be performed next is automatically changed based on the inspection data acquired and accumulated so far.

  Here, the inspection conditions include, for example, the direction of the moving locus for scanning the probe and the moving speed in the case of ultrasonic flaw detection. You may make it include even changing the kind of probe as inspection conditions.

  Here, for example, when changing the direction of the scanning trajectory, the scanning trajectory is further changed slightly from the scanning trajectory in which no defect has been detected to the direction of the scanning trajectory in which the present defect has been detected. If the echo that indicates is increased, the direction of the scanning locus is further changed in the same direction, and if the echo indicating the defect is reduced, the direction of the scanning locus is now slightly returned to the opposite direction. With reference to the defect detection data, it is possible to narrow down the direction of the scanning trajectory in which the defect can be detected with higher sensitivity and to reach the direction with higher sensitivity.

  In this case, the direction of the scanning trajectory with high sensitivity is a right-angle direction that is directly opposite to a defect such as a crack. If the defect end position is detected by detecting flaws in a direction with good sensitivity, the S / N ratio of the reflection component can be increased, so that the defect end position can be automatically detected with high accuracy. .

  At this time, the gain may be automatically adjusted from the received signal of the sensor so as to have an appropriate sensitivity when detecting the end position, or the same scan may be repeated by changing the gain to find the optimum gain. However, the gain sensitivity of the transmitting circuit or the receiving circuit may be changed so that the end position can be detected with the highest accuracy.

  In addition, a three-dimensional end position can be estimated from end echo data acquired from a plurality of directions. Since there are two directions perpendicular to the vertical crack surface, the intersection point on the extension line estimated to be the end from the two directions can be automatically obtained as the end position.

  In addition, since the position can be found in the same way for the end immediately adjacent to the end currently focused, the end locus can be obtained by repeating this process, and the end locus is formed on the plane of the scratch. Will be expressed.

  If the highest sensitivity is not obtained when scanning from the direction opposite to the direction in which the highest sensitivity is obtained, there is a possibility that the surface is a horizontal crack surface. The inspection condition may be automatically changed so that the position (height) of the horizontal crack surface of the inspection object is inspected by changing to a touch.

  Also, if scanning is not possible from the opposite direction in terms of space, changing the probe to one with a different angle of the oblique probe as the inspection condition and narrowing the direction of the end with two types of angles will result in fragmentation. Even in scanning only in the direction, the three-dimensional position of the end portion is scanned from the direction in which the same high sensitivity is reflected, so that it can be accurately estimated.

  At this time, in the second means, in the automatic inspection system of the first means, the probe is a directional probe, and means for changing the direction of directivity is provided in the scanning mechanism and / or the probe itself. .

  In other words, in the case of an ultrasonic probe, an oblique probe is used, and a rotation function is provided in the gripping mechanism portion of the probe of the scanning mechanism so that the direction of the oblique probe can be set to rotate. It is to be.

  The direction of the scanning trajectory with good sensitivity to defects such as cracks is perpendicular to the defect, but when the probe itself has directivity, such as an ultrasonic probe of an oblique probe. In this case, it is preferable to scan the direction of the probe in consideration of the direction of directivity, and of course, if it is necessary to apply the probe so that it faces the defect, the scanning locus is considered. Furthermore, it is necessary to scan the direction of the probe with the directional direction directed toward the defect.

  In that case, if the probe gripper can control the rotation of the probe, it becomes possible to align the probe in the direction that gives the most sensitivity when bringing the probe close to the defect with any scanning trajectory. The edge position of the defect can be detected under more sensitive conditions. As a result, the S / N ratio of the reflection component is improved, so that the edge position of the defect can be found automatically with high accuracy.

  According to the third means, in the automatic inspection system of the first or second means, means for changing the characteristics of the probe is provided in the scanning mechanism or the probe itself, or both. There is also a method of estimating the end position from the scanning trajectory obtained with two types of good sensitivity when specifying the end position of the defect with the acoustic probe, but it is not possible to scan spatially from the opposite direction side of the defect In some cases, as the characteristics of an oblique probe of an ultrasonic probe, the characteristics of the oblique angle specification can be changed by using two kinds of oblique angle specifications, for example, 45 ° and 70 °, and exchanging the probe. Thus, the end portion is found by scanning with a probe having two kinds of characteristics from the same direction.

  In addition, when the crack defect is a surface perpendicular to the plate thickness direction, changing the characteristics of the probe from the oblique probe to the vertical probe allows the crack defect to be detected instead of detecting the edge of the defect. It is also possible to automatically find the range and size of crack defects on the surface perpendicular to the plate thickness direction by measuring the depth of the surface vertically.

  Similarly, according to the fourth means, in the first automatic inspection system, since the scanning mechanism and the probe are two-dimensionally arranged array probes, the two-dimensionally arranged array probes are formed into a two-dimensional sheet shape. It can be easily arranged along the curved part of the cylinder of the pipe or the body plate, and by arranging the array probe in two dimensions, it becomes possible to scan electronically in any direction. It is possible to easily obtain an automatic inspection apparatus having the advantage of applying the means and having no movable part.

  Further, according to the fifth means, the means for detecting the presence / absence of a defect in the automatic inspection system of the first means includes data obtained by actually scanning a healthy inspection object under the same conditions, or data and inspection by simulation results. A means for detecting the presence / absence of a defect based on the degree of coincidence by comparing with the data obtained by scanning the object is added, so that the presence / absence of the defect can be detected easily and accurately.

  In other words, in the case of inspection using reflected waves, such as in the case of an ultrasonic probe, the actual structure of the object to be inspected includes an end as a structure, a part whose shape changes, a welded part, etc. In addition, since various reflections come back, there are cases where it is difficult to judge the reflected wave from the defect or the reflected wave on the structure of the inspection object only by the reflected wave data.

  For example, if reflection data from a healthy inspection target member is acquired in advance under the same conditions as the scanning conditions of the probe and compared with detection data from the probe during actual scanning, reflection obtained from a healthy inspection target member The same part as the data is not a defect, and when reflected wave data is detected in a part that is not the same, it can be easily determined that it is a defective part.

  A method may be used in which a healthy inspection target member is prepared in advance and all inspection data is acquired in advance under the same conditions. However, since preparation in advance is difficult, for example, in the case of an ultrasonic probe, ultrasonic reflection The timing time and magnitude of the reflected wave component returning to the probe in consideration of the wave trajectory, the loss when propagating inside the steel material, and the energy component according to the directivity component at the time of reflection are the shape of the inspection object, It is obtained by calculation by modeling the characteristics.

  Therefore, if the response results under all scanning conditions are calculated in advance by simulation and the results are compared with the actual responses, the automatic inspection can be performed more efficiently and accurately.

  Further, when the simulation calculation speed is sufficiently high, the simulation calculation may be performed under the same conditions as when the probe is actually scanned, and the comparison determination may be made based on the result obtained at that time. As a result, it is not necessary to perform many calculations in advance and record the results.

  Furthermore, according to the sixth means, in the automatic inspection system of the fifth means, the model that performs a simulation when a healthy inspection object is scanned under the same conditions is used, based on previously acquired inspection data. A function that incorporates a defect model to be estimated, compares the data of the simulation result with the data when the inspection object is scanned, and determines whether or not the state of the defect has been sufficiently clarified by the degree of coincidence. Since it is provided, an actual defect can be estimated more accurately.

  In other words, if the defect model incorporated in the simulation matches the actual defect, the result matches regardless of what inspection probe is scanned under what scanning condition. Can be judged to be almost equivalent.

  On the other hand, if the defect model does not match, the defect model is corrected so as to match, whereby the defect model can be brought closer to an actual defect.

  Next, according to the seventh means, in an automatic inspection system that attaches a probe to a scanning mechanism and automatically scans an inspection object and processes a signal from the probe to acquire inspection data, Since the shape measuring means and the means to automatically generate the scanning control data that performs automatic scanning from the measured shape data are provided, the shape is actually measured at the site, and the scanning control data is generated from the measurement result. become able to.

  For this reason, it is not necessary to perform input work for the shape data of the inspection object in advance or work for creating automatic scanning control data such as the scanning trajectory of the probe in advance from the input shape data, so work efficiency can be easily increased. .

  At this time, according to the eighth means, since the shape measuring means in the automatic inspection system of the seventh means adds an unmarked mark to the surface of the inspection object as the image measuring means, it is easy. The shape can be measured. In other words, the field work can be facilitated simply by setting an imaging device such as a camera or illumination as the image measuring means.

  If a camera and illumination are attached to the scanning mechanism in advance, setting of the scanning mechanism enables the setting of the camera and the like at the same time.

  Also, if the inspection object is plain and has no features, you cannot measure the image even if you look at the plain object with the camera, but you can add a mark pattern on the surface of the inspection object or use a shadow on the surface to create a pattern on the surface. If a mark is added so that the image is captured, it is possible to easily measure the surface shape data of the inspection object using a camera that can be easily measured.

  According to the present invention, since the probe can be automatically scanned from the direction with the highest sensitivity to the defect, the sensitivity to the automatic defect detection is improved, and the size and shape of the defect can be inspected more accurately. it can.

  Further, according to the present invention, there is no need to register shape data in advance for inspection objects having complicated shapes such as various pipes, container bodies, and end plates, and it is not necessary to set the inspection apparatus with high accuracy. Automatic flaw detection can be performed easily.

  Hereinafter, an automatic inspection system according to the present invention will be described in detail with reference to embodiments shown in the drawings.

  Here, first, the embodiment of the present invention can be broadly divided into those according to the first technique and those according to the second technique. First, in the embodiment according to the first method, the probe itself has no directivity, and when the probe is moved, sensitivity is improved in the moved direction, that is, the moved direction becomes the directed direction. The second method is an embodiment in which the probe itself is directional from the beginning, and the probe is moved while controlling its orientation. is there.

  By the way, the second embodiment is more widely applied to various probes at this time, and will be described in detail later as a basic embodiment of the present invention.

  On the other hand, in the first embodiment, since the probe itself has no directivity, a mechanism for changing the orientation of the probe is unnecessary, and the configuration of the apparatus becomes simple. Therefore, first, the apparatus configuration in this case will be briefly described with reference to FIGS.

  First, Fig. 1 shows the equipment configuration when periodic inspections are performed on the piping of nuclear power plants and the soundness is confirmed. At this time, there is a problem with radioactivity in nuclear power plants. For this reason, inspection and inspection are performed by remote control.

  In FIG. 1, here, the pipe of the nuclear power plant is the inspection object 1, and the welded part 2 in the pipe and the vicinity of the welded part 2 are inspected and inspected.

  Therefore, the probe 10 is pressed in the vicinity of the welded portion 2 so that the inside can be inspected. At this time, the probe 10 is attached to the arm-shaped scanning mechanism 20 and along the surface of the inspection object 1. The movement can be made by following a predetermined scanning locus.

  For this reason, the scanning mechanism 20 is mounted on the base carriage 25 and is configured to move along the periphery of the inspection object 1 by a track 26 installed around the inspection object 1.

  At this time, the scanning mechanism 20 has five degrees of freedom of rotation angles θ 1, θ 2, θ 3, θ 4, and θ 5 by the five rotation joints, thereby allowing the probe 10 to be arbitrarily positioned on the surface of the inspection object 1. It is configured so that it can be pressed vertically at a position, and the surface can be scanned along an arbitrary trajectory and surveyed (explored or flawed).

  As described above, the base carriage 25 can move around the inspection object 1 along the track 26, so that the entire area including the back side of the inspection object 1 and the welded part 2 that makes one round in the circumferential direction can be obtained. Can be inspected.

  The base carriage 25 and each rotation joint of the scanning mechanism 20 are provided with drive motors and sensors, and each drive motor is controlled by the scanning mechanism control device 50. At this time, the position X of the base carriage 25 and the rotation angle of each rotary joint are detected by each sensor, and the detected information is taken into the scanning mechanism control device 50.

  At this time, the initial scanning trajectory data is recorded in the storage device 42, and the shape information of the inspection object 1 is recorded in the storage device 45. Therefore, the scanning control data generation unit 40 reads each data from the storage devices 42 and 45, calculates and inputs the angle command signal of each rotary joint necessary for realizing the requested scanning locus. .

  As a result, the scanning mechanism control device 50 drives and controls the motors of the joints so that the feedback joint angle information matches the command angle, thereby forming a feedback control loop.

  Here, the signal detected by the probe 10 is taken into the inspection data recording unit 30 and processed to calculate necessary data such as the presence, position, and shape of the defect, converted into a necessary data format, and stored in the inspection data. Recorded in device 35. At this time, the inspection result is supplied to the display monitor 50 as necessary, so that the inspector can check it.

  At this time, as a configuration peculiar to this embodiment, the inspection data obtained by scanning with the probe 10 this time is stored in the inspection data recording device 35 together with the inspection data scanned before that time, and the scanning control data generating unit 40 is stored. The control conditions for reading the past inspection data and determining the next scanning are determined and supplied to the scanning mechanism control device 50. This will be described in detail later.

  By the way, when inspecting the vicinity of the welded part 2 of such an inspection object 1, in the conventional scanning control procedure, first, the probe 10 is positioned at the start point SP, and the probe 10 is pressed against the inspection object 1 there. Generally, the control is performed by repeating the scanning approaching linearly toward the welded portion 2 to make one round in the circumferential direction.

  Then, when scanning control is performed from the start point SP and the point (position) P1 is reached, since there is a defect 3, significant inspection result data can be obtained for the first time. However, this is up to here in the prior art.

  Therefore, when the detection signal is strong or weak depending on the scanning direction of the probe 10 with respect to the defect 3, in the conventional technique, when the direction of the defect 3 is in a direction in which the detection signal does not appear so much, the signal of the inspection result data from the probe 10 is Significant difference is not enough.

  For this reason, when trying to estimate the size of the defect 3 from the signal, even if the scanning density is made fine, the conventional technique scans from the direction in which the signal does not appear much with respect to the direction of the defect 3. Therefore, the accuracy is not good.

  As described above, since the defect 3 generally randomly occurs, the scanning direction may happen to be in an appropriate state, but it is often not probabilistic.

  Therefore, in this embodiment, if even a significant difference signal due to the defect 3 is detected at a certain position, the scanning direction from the position, for example, the point P1 to the defect 3, is indicated by the points P2, P3, and P4 as illustrated. The scanning control data generation unit 40 is configured so that the direction in which the signal level of the inspection result data detected from the probe 10 is maximized is automatically searched.

  Here, as described above, the reflected wave becomes maximum when the ultrasonic wave is applied from the direction facing the surface of the defect 3, that is, the normal direction of the defect 3. Therefore, in the case of the defect 3 in FIG. 1, the reflected wave gradually increases as the scanning trajectory is changed with the points P1, P2, and P3, but when the direction is changed to the point P4, the angle from which it directly faces is exceeded. As a result, the signal level of the detection data is reduced again this time.

  That is, in this case, since the detection signal is the largest at the point P3, if the scanning locus is changed to the points P1, P2, P3, and P4 while monitoring the situation, the signal level becomes low at the point P4. It can be seen that the scanning direction at the front point P3 is the direction facing the surface of the defect 3.

  Here, FIG. 2 shows the defect 3 in an enlarged manner. Here, according to this embodiment, if the scanning direction at the point P3 is the normal direction Pn0 with respect to the defect 3, the defect 3 It is also possible to survey how 3 spreads to the left and right.

  That is, the scanning direction at the point P3 = the normal direction Pn0 is used as a reference, the scanning locus is shifted to the right, the angle is similarly changed at the shifted point, and the signal level of the inspection result data is maximized. Survey (normal direction).

  Then, the normal direction Pn1 at this point is obtained, and the normal direction at the point Pn2 slightly shifted to the right side thereof, the normal direction at the further right point Pn3, and so on, at each point Pn4, Pn5. By detecting the normal direction, the spread of the defect 3 can be obtained.

  At this time, since the defect 3 has disappeared on the right side from the point Pn5, it is possible to accurately detect that the position of the point Pn5 is the right end of the defect 3 by monitoring the detection data signal. By detecting the normal direction on the left side of the defect 3, the left end can also be detected with high accuracy.

  In these survey processes, the current detection data obtained from the probe 10 and the previous detection data obtained from the storage device 35 are referred to by the scanning control data generation unit 40, and the trajectory data to be scanned next is generated by Can be done automatically.

  A specific processing flow of the scanning control data generation unit 40 at this time will be described later with reference to FIG.

  At this time, the position information of the detected defect 3 is read from the inspection data 35 by the display control device 60C, and displayed on the display monitor 60 in a plan view, so that the shape and length viewed from above the defect 3 can be obtained. It can be recognized accurately.

 At this time, the length of the defect 3 may be obtained numerically from the edge position data of the defect 3 and displayed on the display monitor 60.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, here, the case of an ultrasonic probe will be described as an example of a probe having directivity, but if it is a probe having directivity, an eddy current sensor, a magnetic sensor, an electrostatic sensor, a radiation sensor, etc. It does not ask the type of sensor.

  Also, the inspection object is not limited to metal such as food, resin, earth such as the earth, and rock. Here, the case where the ultrasonic sensor which inspects the defect in a metal is used is mentioned as an example.

  Here, in the case of FIG. 1, the scanning mechanism 20 is an arm type, whereas in the embodiment described below, the scanning mechanism 20 has two X-axis and Y-axis as shown in FIG. 3. It is a shaft drive type. However, the configuration of the scanning mechanism 20 may be any scanning mechanism as long as the scanning control of the probe 10 can be performed.

  In FIG. 3, the scanning mechanism 20 includes a feed screw 21 and a feed nut 22, is mounted on a base carriage 25, can move in the X direction on the track 26, and moves the feed nut 22 in the Y direction by the rotation of the feed screw 21. Be able to.

  At this time, since the probe 10 has directivity, the feed nut 22 is provided with a rotation mechanism provided with a rotation motor 23 so that the orientation θ of the probe 10 can be changed.

  Therefore, the scanning mechanism 20 of FIG. 3 is controlled by the scanning mechanism control device 50 in the X-axis direction and the Y-axis direction and the probe orientation θ, and as a result, the probe 10 is pressed against the surface of the inspection object 1. In this state, the scanning direction can be controlled in an arbitrary direction in consideration of the directivity of the probe 10.

  In this embodiment, the probe 10 has directivity, so that when the scanning direction is changed at each point P1, P2, P3, P4, the rotary motor 23 is adjusted so that the directionality of the probe 10 is aligned with the scanning direction. Is controlled to control the direction θ.

  In addition, when using a probe with directivity in this way, it is necessary to control the direction θ, but when compared with a probe with no directivity, energy for flaw detection can be concentrated in one direction, As a result, a large reflected energy can be obtained, so that defects and the like can be detected with higher sensitivity.

  Here, FIG. 4 shows an example of a specific structure of the rotation mechanism for aligning the directing direction of the probe 10 with the scanning direction. At this time, the probe 10 is an ultrasonic probe, and an inspection is performed. The surface of the object 1 needs to be contacted and scanned. Therefore, a shoe 101 is provided at the tip of the probe 10 to make it easy to slide.

  At this time, a pressing spring 104 is provided in a state in which the probe 10 is placed in the storage cylinder 103, whereby the probe 10 is pressed against the surface of the inspection object 1 with a constant force.

  In FIG. 3, the probe 10 is pressed against the surface of the inspection object 1 with a constant force using the spring 104. However, the pressing force of the probe 10 is detected by a sensor, and the detected probe is pressed. For example, in the case of the arm-type scanning mechanism 20 of FIG. 1, the probe 10 is pressed by a predetermined force by controlling the actuator at the joint portion of each arm so that the force becomes a predetermined constant value. You may control.

  In the case of the XY two-axis drive type scanning mechanism 20 in FIG. 3, a dedicated actuator for pressing may be provided, and the actuator may be controlled so that the pressing force detected by the sensor becomes constant.

  Here, the scanning accuracy of the scanning mechanism 20 is not so high that the scanning mechanism 20 can be pressed from the normal direction of the inspection object 1 and can be scanned with zero error. Therefore, a gimbal mechanism 102 is provided in the storage cylinder 103 in which the probe 10 and the spring 104 are stored, and the probe 10 is attached to the scanning mechanism 20 by the gimbal mechanism 102.

  The rotational force of the rotary motor 23 is transmitted to the gimbal mechanism 102 via a gear or the like. From this, the direction θ of the probe 10 is controlled, and the signal detected by the probe 10 is a cable. 105 is taken out.

  Therefore, the scanning direction at the point P4 in FIG. 3 is indicated by an arrow in FIG. 4, the probe 10 is moved in this direction, and ultrasonic waves are emitted sequentially from the point P4 (1), and the response is probed. Assume that scanning is performed in such a manner as to be detected at 10.

  Then, if there is a defect 3 in the inspection object 1, since the ultrasonic wave is reflected by the defect 3 between the point P4 (2) and the point P4 (3), a significant difference appears in the detection result signal. At the point P4 (4), the inspection result data is obtained in a state where the reflection from the defect 3 is eliminated.

  The response waveform of the signal at this time is shown in FIG. Here, in FIG. 5, the horizontal axis represents time and the vertical axis represents the signal level, and the output signal is represented.

  At this time, FIG. 6 shows an example of the cross-sectional state of the inspection object corresponding to the signal of FIG. 5, and in these FIG. 5 and FIG. There is a signal at the time of transmission, but no response is returned.

  Next, since the reflected wave from the defect 3 returns from the point P4 (2) to the point P4 (3), the signal at the point P4 (2) is the defect 3 (a) part after t (a) max time. Appearing as a reflected wave from, and its signal level is the maximum value S (a) max.

  Similarly, at point P4 (3), a reflected wave S (b) max from the defect 3 (b) appears after time t (b) max. However, at point P4 (4), there is no reflected wave here.

  At this time, the amount obtained by multiplying the moving speed in the P4 direction by the ultrasonic transmission interval (time) at each point P4 (1), P4 (2), P4 (3), P4 (4) is P4 of the probe 10. It represents the amount of movement in the direction.

  As described above, FIG. 5 shows the state in a cross-sectional view along the scanning direction P4 of the inspection object 1. Here, the probe 10 has points P4 (1), P4 (2), P4 (3) and point P4 (4) are sequentially moved. A reflected wave from the defect 3 is detected between the point P4 (2) and the point P4 (3).

  At this time, the distances L (a) and L (b) can be obtained by multiplying the times t (a) max and t (b) max at which the respective reflected waves appear by the sound speed. Therefore, assuming that the directivity characteristic of the probe 10 is in the direction of the angle α, the positions of the defect 3 (a) and the defect 3 (b) can be specified.

  By the way, the characteristic in the normal direction of the defect 3 is not only the characteristic in the normal direction when seen in the plan view of FIG. 2, but also the inspection object 1 in the scanning direction at the point P3 in FIG. There are characteristics when you do.

  Here, FIG. 7 shows a cross-sectional view of the inspection object 1 in the scanning direction of the point P3, but here, an example in the case of transmitting an ultrasonic wave more finely and detecting a response is shown. In this case, the range in which the reflected wave appears from the defect 3 is between the point P3 (1) and the point P3 (8).

  At this time, the directivity of the probe 10 is the direction of the angle α, and the reflection of the ultrasonic wave coming from this direction is detected. However, the defect 3 by this cross section also has a normal direction and faces the defect 3. When an ultrasonic wave is transmitted from the normal direction, a large reflected wave is received by the probe 10, and a signal with a large level is detected.

  Therefore, if an ultrasonic wave is transmitted in the direction of the angle α at the point P3 (5), the ultrasonic wave is incident on the point A1 of the defect 3, and the reflected wave reflected here is indicated by a thin arrow, Assume that it has a level of RP3 (5) α.

  At the point A1, the ultrasonic wave from the point P3 (5) has a large reflected wave because the incident angle α is substantially normal to the defect 3.

  On the other hand, the ultrasonic wave input at an angle α from the point P3 (6) is incident on the point B of the defect 3 and is reflected here, but the inclination is larger than the angle α on the surface of the point B. The level RP3 (6) α is small.

  Here, if the pointing direction of the probe 10 is set to the angle α2 instead of the angle α, in this case, the ultrasonic wave incident from the point P3 (8) is almost directly opposed to the defect 3, and the level A large reflected wave level indicated by RP3 (6) α2 is obtained.

  Thus, even in the cross section of FIG. 7, the defect 3 has a normal direction, and in order to detect it, it is necessary to survey by changing the directivity angle α of the probe 10, but the size of the defect is further increased. If you don't need to know in detail, you don't have to do that.

  However, if the sensitivity is too low, prepare three types of directivity angles α of 45 degrees, 70 degrees, and 90 degrees, and use them properly so that the shape and dimensions of the defect 3 can be detected with higher sensitivity. This will be described later.

  Hereinafter, the case where the shape and size of the defect 3 are surveyed without changing the directivity characteristic of the probe 10 without changing the angle α will be described. First, here, in FIG. And the normal direction when viewed from the AA cross-sectional direction of the point A1 is surveyed.

  Therefore, one point of this point A1 is sequentially scanned from the direction of each point P1, P2, P3, P4, P5 as shown in FIG. Then, the direction is the normal direction of the defect 3 when viewed from the AA cross section.

  Similarly, the angle α at the points P3 (2), P3 (3), P3 (4), P3 (6), P3 (7), P3 (8) in order from the reflection point in the angle α direction at the point P3 (1). For each reflection point, the normal direction in the plan view direction (= direction of the AA cross section) is examined, and the direction in which the defect 3 spreads can be known.

  In this case, the angle α cannot be adjusted to the optimum value, but a large sensitivity can be obtained by adjusting the scanning direction in the plan view direction to the normal direction, so that the defect status can be known more accurately. .

  Of course, it is more time-consuming to detect the three-dimensional accurate normal method with respect to the surface of the defect 3 by changing the angle α, but it is possible to survey the state of the defect more accurately. Absent.

  The survey process at this time refers to the detection result data from the probe 10 and the previous test result data read from the storage device 35, and the scan control data generation unit 40 generates trajectory data to be next scanned. This can be done automatically.

  Note that the specific processing flow of the scanning control data generation unit 40 at this time will be described later with reference to FIG. 17 as described above.

  Next, FIG. 9 is an example in which the result of surveying the shape of the defect 3 is conceptually shown, and the shape of the defect is represented as a defect on the surface formed by each of the reflection points R11 to R54, and at this time the pointing direction Although the angle α may or may not be changed, a situation is shown in which the normal direction at each of the reflection points R11 to R54 is detected.

  Needless to say, the narrower the directional characteristics of the probe 10, the better the shape detection resolution.

  Since the result of surveying the shape of the defect 3 as shown in FIG. 9 is recorded in the recording device 35 as inspection data, the position data of the defect 3 in the recording device 35 and the numerical information of the shape data are displayed and controlled. If read by the device 60C, the defect 3 can be displayed on the display monitor 60 as a three-dimensional graphic (three-dimensional CG).

  As described above, if the shape of the defect 3 is displayed by the three-dimensional graphic, the position of the viewpoint when the defect is displayed can be changed by a general function provided in the three-dimensional graphic. The shape can be easily grasped by checking the shape from various angles.

  At this time, a scale may be displayed on the display monitor 60 so that the size (rough size) of the defect 3 can be referred to at a glance, or two arbitrary points of the defect 3 displayed on the display monitor 60. May be displayed on the screen of the display monitor 60 by inputting an operation with a mouse or a penlight.

  Therefore, according to the above embodiment, scanning is automatically performed from the direction most sensitive to the defect 3, that is, in the case of an ultrasonic probe, generally perpendicular to the defect or the like. As a result, the sensitivity to automatic defect detection can be increased, and the result can be displayed visually to inspect the size and shape of the defect with higher accuracy.

  Next, the probe used in the present invention will be described. First, FIG. 10 shows an example of a so-called electronic scan type probe in which directivity characteristics are electrically changed using an ultrasonic array sensor. The ultrasonic array sensor is composed of a plurality of probes 10 (1), 10 (2),..., 10 (n).

  Here, in FIG. 10, n = 11, that is, the total number of probes is 11, and these probes 10 (1) to 10 (n) are arranged in a line, and the object to be inspected. The entire surface is covered with a shoe 101 so as to be in contact with the surface of 1 and perform flaw detection.

  Each probe 10 (1), 10 (2),... 10 (n) is fired from each probe by slightly shifting the timing of the excitation signal for transmitting the ultrasonic wave. In this way, directivity appears in a specific direction.

  In FIG. 10, as an example, a case where the focal point of the emitted ultrasonic wave is controlled to be a point F is shown. However, at this time, an arbitrary distance and a predetermined distance are determined depending on how the excitation signal is supplied. It is possible to concentrate the ultrasonic wave at a position distant from the direction.

  As described above with reference to FIG. 7, one of the directivity characteristics of the probe can be obtained by using the electronic scan type array sensor that can arbitrarily control the direction in which the sound wave is transmitted and the focal point for concentrating the sound wave. The scanning control of the probe 10 can be performed while arbitrarily controlling the angle α, and a more detailed and accurate survey is possible when surveying the normal direction of the surface of the defect 3.

  Even if a detailed survey is not required here, if there is only one angle α, the surface of the defect 3 that faces the angle α is easy to detect, but on the other hand, most of the reflected waves are parallel to the surface that is parallel to the angle α. Since it does not return toward the probe 10, the detection sensitivity (S / N) of the defect 3 is lowered.

  However, even in such a case, if the probe of FIG. 10 is used, the angle α can be slightly changed, so that the detection sensitivity of the defect 3 can be increased, and the size and shape of the defect 3 can be inspected accurately. Can do.

  Next, FIG. 11 shows an example in which a plurality of probes 10 (n) are arranged along the surface of the virtual sphere 10a with the point O as the center to form an array sensor. Each child 10 (n) is directed in a different radiation direction from the point O.

  Therefore, if the probe used for the survey is selected from the plurality of probes 10 (n), the ultrasonic wave can be easily transmitted in the required direction. Therefore, in this case, the subtle transmission is performed. There is no need to control the timing, just select the probe that is facing the required direction.

  Further, in this case, since the ultrasonic waves are emitted radially around the point O of the virtual sphere 10a, the process of calculating the defect position serving as the reflection point from the reflected wave is facilitated.

  Even in the case of an array sensor in which probes are arranged in this way, the directivity may be given by finely controlling the timing of transmission.

  Here, only one row of the plurality of probes 10 (n) may be arranged on the surface of the virtual sphere 10a. In this case, the probe 10 (n) is arbitrarily arranged in the direction in which the probes 10 (n) are arranged in one row. For example, if the probe is used as the probe 10 in FIG. 3, it is only necessary to control the angle θ by the rotary motor 23.

  On the other hand, as shown in FIG. 11, if a plurality of probes 10 (n) are three-dimensionally arranged on a part of the spherical surface of the virtual sphere 10a, the directivity direction can be selected only by selecting each probe. Since the angle α and the angle θ can be controlled, for example, if the probe is used as the probe 10 in FIG. 3, the rotation mechanism by the rotation motor 23 can be omitted.

  10 and 11 show the case where an array sensor is applied to the probe and the directivity characteristics of the probe 10 itself are changed. In the embodiment described below, a plurality of probes having different characteristics are used. Is prepared, and the probe is exchanged as necessary for the survey.

  Here, FIG. 12 shows the embodiment. Here, a teaching / playback type robot equipped with an arm-type manipulator is used as the scanning mechanism 20, and the base carriage 25 of the operation mechanism 20 is inspected along the track 26. The object 1 can be moved to a position where it can be accessed to some extent on both sides.

  At this time, the probe attaching / detaching mechanism 10 c is provided at the tip of the scanning mechanism 20, so that the probe 10 can be attached to and detached from the tip of the scanning mechanism 20. And according to this, the probe stand 10b is provided, and it has comprised so that several other probes from which the characteristic differs may be prepared for this.

  Then, while the inspection object 1 is being surveyed using a certain probe 10 by the scanning mechanism 20 composed of this arm type robot, the probe 10 is moved to another lobe having a directional characteristic required according to the scanning direction. And can be automatically replaced.

  The automatic replacement of the probe 10 at this time is performed as follows. That is, first, the lobe mount 20b is attached to the same frame as the base carriage 25 and the track 26 of the scanning mechanism 20, and the positional relationship between the probe mount 20b and the probe attaching / detaching mechanism 10c at the tip of the scanning mechanism 20 is known. To be.

  On the premise of this, the robot of the scanning mechanism 20 is taught in advance, so that the probe 10 can be automatically replaced by automatic playback operation in the same manner as the normal manipulator control. It is.

  Therefore, in this embodiment, a series of automatic operations is performed in which the currently gripped probe 10 is returned to a predetermined position on the probe mount 20b, and thereafter a probe having another characteristic is gripped and returned to the original survey position. As an operation.

  The operation control data necessary for teaching and playback at this time is given to the scanning mechanism control device 50. Therefore, the scanning control data generation unit 40 determines the probe characteristics that are a kind of scanning control conditions from the previous inspection data. When the change data is generated, the playback operation is executed when the probe replacement command is output to the scanning mechanism control device 50 as part of the scanning control data.

  Further, the type and performance of the probe to be replaced at this time are input to the scanning mechanism control device 50 in advance, and the changeover switch 10e is switched correspondingly, and the signal from the selected probe is sent to the inspection data recording unit 30. And is controlled so as to be correctly input to the scanning control data generation unit 40.

  In this way, if a plurality of probes having different characteristics are prepared, the probe characteristics can be easily changed each time during the automatic inspection simply by exchanging the probes held by the scanning mechanism 20. It becomes like this.

  At this time, since the scanning mechanism 20 originally has a function capable of performing automatic operation control, it is possible to easily change the probe characteristics simply by using it.

  On the other hand, if there is sufficient space around the inspection object 1 that scans the probe and there is no problem even if the gripping portion of the probe 10 at the tip of the scanning mechanism 20 becomes large, the tip of the scanning mechanism 20 is preliminarily provided. A plurality of probes are provided, one of the probes is selected by a selection command signal, and a mechanism for moving the probe to a predetermined position, that is, a position required for the survey is provided. The probe may be changed to a different probe.

  Therefore, according to the above embodiment, the characteristics of the probe 10, that is, the directivity angle α, the focal length, the beam spread characteristic, and the like are appropriately set according to the state of the inspection result data so far during the inspection. As a result, the defect investigation can be automatically performed more accurately and continuously in detail.

  Next, FIG. 13 is also an example of an electronic scan type probe used in the embodiment of the present invention. This is a plurality of probes, in this case 121 ultrasonic probes (= 11 × 11). ) Two-dimensionally arranged.

  Here, in FIG. 10 described above, the probe is arranged in a one-dimensional configuration, but in the example of FIG. 13, it is arranged two-dimensionally, and at this time, each probe is further arranged. A sheet-like two-dimensional array sensor is attached to a flexible sheet-like member.

  As a result, adjacent probes can be easily bent at the portion where the sheet-like members are connected, and when applied to an inspection object having a curved surface such as a pipe, the adjacent probe is bent along the curved surface. All of the three-dimensional probes can be pressed against the inspection target part from the front.

  Therefore, according to the probe comprising the sheet-like two-dimensional array sensor shown in FIG. 13, the electronic scan control is performed assuming any combination of the one-dimensional array sensors from the two-dimensionally arranged probes. In this manner, scanning control in an arbitrary direction can be performed only by electronic scanning control without using the mechanical scanning mechanism 20.

  Specifically, in FIG. 13, for example, when it is desired to have a directivity characteristic of an angle α and to scan in the Pi direction, as shown in FIG. Probes a8, b8, c7, c8, d7, e7, f6, f7, g6, h6, i5, j5, k5, l4, and l5 arranged in the Pi direction are selected, and these are used as a one-dimensional array sensor. Is virtually formed.

  The one-dimensional array sensor described with reference to FIG. 10 is controlled by electronic scanning control, that is, by sequentially performing transmission control at a predetermined timing in consideration of the distance between the probes arranged in the Pi direction. The same thing as when the scanning control is performed in the Pi direction can be realized without performing any mechanical scanning control.

  Therefore, in the case of the probe shown in FIG. 13, only the work of covering the inspection object 1 with the sheet in a predetermined direction at a predetermined position is performed first, and then the detailed shape and size of the defect 3 are all controlled by electronic scan control. Can be inspected in detail.

  Next, FIGS. 14 and 15 show the probe unit 10Asm as the probe based on the virtual sphere 10a described in FIG. 11, and are connected to each other by a foldable mechanism indicated by a double circle in the figure. This is an example when the probe is two-dimensionally arranged.

  At this time, as shown in FIG. 15, the number of the plurality of probe units 10Asm is 121 (= 11 × 11) and is two-dimensionally arranged here.

  Here, the units 10Asm may be connected by a rotatable mechanism as shown in FIG. 14, or may be connected by a sheet-like flexible member as in the case of FIG.

  At this time, if the object to be inspected has a three-dimensional curved surface such as a boiler end plate, the distance between the probe units 10Asm is further increased so that the object can be fit well. If the probes are connected to each other in consideration of the number and arrangement of the probe units 10Asm according to the curved surface shape to be fitted in advance, all the probes are correctly connected to the three-dimensional curved surface. It will be possible to cover in the state against.

  Further, when the probe unit 10Asm is two-dimensionally arranged as a probe in this way, ultrasonic waves are not simultaneously transmitted from a plurality of light-colored units 10Asm as shown in FIG. It is recommended that the distance between the tentacles be as narrow as possible so that they can be arranged with high density.

  Here, in the example of FIG. 14, the space between the inspection object 1 and the probe is not filled with a shoe as in the example of FIG. 11, but is filled with a liquid or gel-like contact medium 9. As a result, it can be set to fit a curved surface more stably.

  If such a two-dimensional array sensor is used as the probe 10 so as to cover the inspection object 1, a mechanical scanning mechanism is not necessary, but a probe having more characteristics can be electronically scanned. As a result, the defect 3 can be inspected more quickly and reliably because there is no mechanical scanning.

  At this time, if it is combined with a mechanical scanning mechanism or the sheet is reset by an inspector and the whole sheet is slightly shifted, the distance between the center points O of the probe units 10Asm is equivalently equivalent. As a result, the resolution is further improved, and the inspection can be performed more finely.

  Next, an embodiment of the present invention will be described in more detail with reference to FIG. Here, the embodiment shown in FIG. 16 is provided with a storage device 70 for storing simulation results, a storage device 80 for storing simulated defect data, and a simulator 85 in the embodiment described in FIG. As a result, a further simulation function is added to the scanning control data generation unit 40.

  In this embodiment, there are a first operation mode and a second operation mode. First, the operation in the first operation mode will be described.

  In the case of the first operation mode, an inspection object 1 having no defect is prepared in advance, and its type data, shape data, and the like are used, and a predetermined condition, that is, initial scanning control is performed from a predetermined position by a probe 10 having predetermined characteristics. Scanning is performed under conditions based on the data, and the response signal of the probe 10 is obtained by a computer.

  Now, assuming that the probe 10 is an ultrasonic probe, in this case, depending on the directivity characteristic and spread characteristic of the ultrasonic wave, the actual reflection location such as the location reflected by the shape of the inspection object, the attenuation constant of the sound pressure level when reflected, etc. It is possible to simulate (simulate) an appropriate numerical value from the material characteristics of

  In other words, it is possible to calculate up to the signal level when it is converted into an electrical signal by the probe, depending on the time it takes for the reflected component to return from the probe and the sound pressure level when it returns. Therefore, for example, a response waveform as already described with reference to FIG. 5 can be obtained by a simulation by a prior computer.

  Therefore, the above is calculated in advance in all cases of the scheduled scan data in the initial scanning control data storage device 42 and the result is recorded in the simulation result storage device 70.

  The stored results are compared on the same time axis scale as the signal from the probe 10 when the probe 10 is actually scanned under the scanning conditions of the storage device 42 of the initial scanning control data.

  The simulation result data at this time is calculated on the assumption that the inspection object 1 has no defect. Therefore, when there is a response to the signal from the actual probe 10 without the simulation result data. It can be easily determined that it is a signal from a defect.

  For example, when the inspection object 1 does not have a uniform plate thickness and has a step in the middle, it is not actually a defect, but the ultrasonic wave is reflected, so the signal from the probe alone is seen. Therefore, it is not easy to determine whether it is due to a defect or due to a thickness change portion.

  Therefore, as described above, if the reflected wave obtained from the shape characteristics is obtained in advance by simulation, it is easy to determine that the reflected wave is not a defect.

  At this time, scanning control data from the scanning control data generation unit 40 (characteristic data such as the type of probe, that is, probe directivity) in the system, and shape data from the recording device 45 of the shape data to be inspected ( The simulator 85 that inputs the data including the internal notch shape, plate thickness shape, material characteristics, etc.) and simulates the response signal of the probe 10 may be incorporated.

  In this case, high-speed calculation processing is necessary so that simulation can be performed in real time, but it is not necessary to prepare many simulation results in the recording apparatus 70 in advance, and the scanning control data generation unit 40 has generated. Since the scanning trajectory can be compared with the simulation, the presence or absence of a defect can be detected with higher accuracy.

  Next, the operation in the second operation mode will be described. In this case, the simulation result of the simulator 85 is further recorded in the recording device 70 and not only inputted to the scanning control data generating unit 40 but also recorded in the inspection data. The simulation result is also input to the unit 30.

  Then, the inspection data recording unit 30 records the actual inspection result data from the probe 10 in association with the actual posture information and position information of the scanning mechanism 20 at the same time, and compares it with the simulation result to determine the defect. A signal corresponding to the data is extracted, defect data serving as such a response signal is estimated, and the estimation result is recorded in the storage device 80 as simulated defect data.

  As a result, the simulator 85 performs a simulation when there is no defect and a simulation when the simulated defect data of the simulated defect data 80 is used as a simulation result used when detecting defects with high sensitivity.

  The simulation result incorporating the simulated defect data in the storage device 80 indicates that the simulated defect data in the storage device 80 is the same as the actual defect depending on whether the signals from the actual probe 10 match. Used as a means of confirmation.

  If they are not the same, the inspection data recording unit 30 compares the simulated defect data in the storage device 80 with the signal from the actual probe by comparing the simulation result with the signal from the actual probe. change.

  As a result, if the signal from the actual probe 10 and the output result of the simulator 85 when the simulation is performed by incorporating the contents of the simulated defect data 80 match, the simulated defect data can simulate the actual defect with high accuracy. It will be.

  By doing so, inspection result data that can estimate the shape and size of the actual defect with higher accuracy can be obtained as the simulated defect data 80. At this time, the display monitor 60 displays the actual inspection data and simulation results from the probe 10 or simulated defect data as necessary so that they can be confirmed.

  Here, when displaying the simulated defect data on the display monitor 60, if it is displayed as a 3D (three-dimensional) CG image, the defect can be observed while changing the viewpoint in an arbitrary direction under an arbitrary visual field. It can be monitored more easily.

  In this case, if the shape data of the inspection object 1 is also displayed as a 3D CG image, the display becomes easy to understand.

  Here, a specific processing flow by the scanning control data generation unit 40 in the embodiment described above will be described with reference to FIGS. 17A and 17B and a flowchart of FIG. 17C.

  Here, as a basic processing flow, when starting, the shape data to be inspected is first read in processing 40a. The shape data at this time may include the material characteristics and thickness of the inspection object 1 and notch information inside.

  Next, in process 40b, initial scan control data is read. The scanning control data at this time includes information on what kind of probe is used, what kind of scanning locus, and in what order.

  At this time, as a general scanning trajectory, the entire inspection target part of the inspection target 1 is surveyed by a zigzag path or a rectangular folding path, and a defect is not detected by surveying along the entire path. It is preferable to set a scanning trajectory so that it can be said that there is no defect larger than a predetermined size in the range.

  In the next process 40c, the current posture, position information, and probe setting information of the scanning mechanism 20 are read. In the subsequent process 40d, a control command is issued so that the posture, position, and probe settings of the scanning mechanism are matched with predetermined conditions. Output to the controller 50. This is because predetermined scanning control based on the initial scanning control data is performed, and it is necessary to match when the start condition is not met.

  Next, in operation 40e, an operation command for the scanning mechanism that performs the first predetermined scanning control based on the initial scanning control data is output to the scanning mechanism controller 50 to actually perform scanning control, and in the next processing 40f, actual scanning is performed. The inspection data from the probe 10 is read, and processing for detecting the presence or absence of a signal from the defect in the inspection data is performed.

  Here, the defect data may be detected with high accuracy by comparing with the simulation result data in the case where there is no defect as described above.

  In the next processing 40g, the subsequent processing is divided depending on whether a defect signal is detected or not. If no defect is detected, that is, “No”, the process returns to the process 40e via the process 40i.

  Thus, the next scanning control is repeated based on the predetermined scanning control data, and if it is determined in the process 40i that the survey under all the prepared scanning conditions has been completed, there is no defect that can be detected under the prepared scanning conditions. This process ends.

  On the other hand, when a defect signal is detected in the process 40g, that is, "Yes", the process proceeds to the process 40h, and as described with reference to FIG. 5, the defect positions L (a) to L (b) of the inspection data and the defect signal Processing for detecting MAX levels S (a) max to S (b) max is performed.

  At this time, it is desirable to finely divide the defect positions L (a) to L (b) into equal pitches as described in FIG. 7, and in this case, a more detailed survey can be obtained. Therefore, it is preferable.

  In the next process 40j, the trajectory data obtained by slightly changing the scanning direction in one direction as described with reference to FIG. 8 with the defect position L (i) as the center with reference to the trajectory data of the scanning control data in which the defect is detected. Is generated based on the shape data of the inspection object, and a control command is output to the scanning mechanism control device.

  At this time, the first defect position L (i) is set to the position of one end of either position L (a) or position L (b), and then the next defect position divided at equal intervals is used. It is easy to understand that the processing is sequentially performed so as to obtain the position L (i).

  In the next process 40k, the inspection data of the actual scanning result executed in the process 40j is read, and the presence or absence of a signal due to a defect from the defect position L (i) is detected in the inspection data. Thereafter, in the discrimination process 40l (lower case L), the process is divided depending on whether or not there is a defect signal.

  First, when there is a defect signal, that is, when “Yes”, the process proceeds to 40 m, and the defect signal MAX level S (i) max at the defect position L (i) of the inspection data is detected and detected first. Compare with the signal level at the time.

  In the process 40n, it is determined whether or not the signal level has increased. If it is determined that the signal level has increased, that is, if "Yes", the scanning direction is further changed in that direction. If scanning control is performed, it means that the signal level of the probe 10 is further increased (more normal to the defect surface).

  Therefore, at this time, the process proceeds to process 40o, and the scanning trajectory data is generated based on the shape data of the inspection object as trajectory data in which the scanning direction is slightly changed in the same direction around the defect position L (i), and is controlled. The command is output to the scanning mechanism control device 50.

  Similarly, the process returns to the process 40k, and the scanning direction is changed in the same direction while the defect signal MAX level S (i) max at the defect position L (i) continues to increase.

  Thus, when there is no tendency to increase and “No” is determined in the determination process 40n, this time, after the process 40p, the defect position L (i) when the scanning direction is changed in the opposite direction in the process 40q. In the same way, the defect signal MAX level S (i) max is surveyed until there is no tendency to increase, and if it becomes “No” in the process 40n and further becomes “No” in the process 40p, the reverse direction is included. In the process 40r, the direction in which the largest defect signal is obtained in the inspection data scanned and changed in various scanning directions around the defect position L (i) is defined as the defect surface. The normal direction is recorded in the inspection data.

  Here, the fact that a sufficient defect signal MAX level S (i) max is obtained as a result of scanning from various directions means that there is definitely a defect at the defect position L (i), which means that the simulated defect data The information about the normal direction characteristic may also be recorded in 80.

  Here, when the defect signal MAX level S (i) max cannot be obtained at a sufficient level, specifically, when the S / N is about a significant difference, the result is obtained even if the angle is changed variously. There is a possibility that the defect position L (i) has no defect.

  Therefore, in this case, in order to perform the survey more reliably, the directivity characteristic of the probe 10, for example, the angle α is changed to a different angle, and the same survey is performed. For example, at this angle α, there is a possibility that the S / N ratio may have been bad due to a parallel defect, so two or three types of probes, for example, 45 °, 70 °, and 90 ° angle α, are still used for inspection. If the result is not a signal having a significant difference, it may be determined that the defect position L (i) does not really have a defect.

  Further, in this embodiment, when the scanning angle is changed to the left and right, the flow of processing when the angle to be changed at that time is set to a small angle from the beginning to increase the resolution of the survey is shown.

  However, at this time, in order to increase the survey efficiency, it is changed at a large angle at first, and when the increasing tendency becomes gentle, it is changed at a small angle in the reverse direction. The direction in which the maximum peak of the defect signal MAX level S (i) max can be obtained can be more efficiently surveyed while the angle to be gradually changed is reduced, such as by further reducing the angle to be changed. Good.

  As described above, when the survey for one defect position L (i) is completed, the process returns from the process 40t to the process 40j, and the same process is performed for the adjacent defect position L (i = i + 1). In the determination process 40S, if the survey has been completed over all the positions between the defect positions L (a) to L (b) that were initially equally divided, the process proceeds to process 40u.

  In this process 40u, while scanning control for checking the normal direction of the defect position is being performed, a newly detected defect position may be included in the process 40u. Therefore, the defect position is processed from the first 40h. Similarly, the normal direction of the detected defect is surveyed for all positions that are considered to be all defect positions.

  If it is determined in the process 40v that all the normal directions of the newly detected defect position have been examined, the process returns to the determination process 40i and the remaining scanning control data initially planned. Return to processing.

  When the survey is completed for all the defect positions newly detected in the discrimination process 40v in this way, in the next process 40w, the scan trajectory data is scanned for trajectory data that has not yet been scanned, or the probe characteristics are changed. Then, we survey whether there are any other defects.

  Here, the process of further scanning the periphery of the detected defect to examine the defect state in more detail is the reason why the defect position data originally examined in this process 40u is the normal line of the defect found first. When surveying a direction, this is only a process when a defect is found in a new direction that happens to be scanned, and the survey is not necessarily sufficient to know the overall shape and size of the defect. Because.

  For this reason, in the process 40w, the vicinity of the defect once detected is subjected to a process of actively surveying whether there is any other part where the defect continues, and this leads to the defect first discovered. It becomes possible to detect a defect and a defect existing in the vicinity more reliably and accurately.

  For this reason, in the next discrimination process 40x, it is checked whether or not the state of the defect is sufficiently clarified, and when it is sufficiently clarified, the process returns to the next predetermined scanning control pattern. At this time, in the process 40x, it is confirmed that the simulation result executed by the simulator 85 using the simulated defect data read from the storage device 80 and the data obtained by the actual probe 10 sufficiently match under various scanning conditions. Then, it may be determined that it has become clear enough.

  By the way, the flow of processing according to the flowcharts of FIGS. 17A to 17C described above is the basic processing of the present invention. Therefore, the inspection system including the mechanical scanning mechanism of FIGS. 1, 3, 12, and 16. It can also be applied to the scanning control data generation unit of FIG. 13, and in the embodiment in which the sensor (probe) is arranged in two dimensions described with reference to FIGS. 13 and 15, only electronic scanning is performed instead of mechanical scanning. Similarly, it can be applied in the same way.

  Next, still another embodiment of the present invention will be described with reference to FIG. Here, the embodiment of FIG. 18 corresponds to the embodiment of FIG. 12 in which the TV camera 90, the shape data generation unit 900, and the lighting devices 95 (1) and 95 (2) are added. Are the same.

  First, the TV camera 90 is attached in the vicinity of the probe 10 and functions to supply an image signal to the shape data generation unit 900 by imaging the surface of the inspection object 1 centered on the survey point by the probe 10. .

  Next, the shape data generation unit 900 processes the image signal input from the TV camera 90 to represent data representing the surface shape of the inspection object 1 and the relative position and orientation relationship between the TV camera 90 and the inspection object 1. Work to ask for data.

  As described above, if the surface shape of the inspection object 1 and the relative position and orientation relationship are obtained, the initial set position error of the scanning mechanism 20 in the field can be correctly calibrated (corrected). Accordingly, it is not necessary to set with high accuracy in consideration of the positional relationship of the inspection object with respect to the scanning mechanism of the inspection apparatus.

  Further, if the surface shape of the inspection object 1 can be easily obtained from the image information captured by the TV camera 90 as described above, it is not necessary to input the shape data to be inspected into the storage device 45 in advance. .

  However, even in this case, it is difficult to measure the notch and the plate thickness data inside the inspection object 1. Therefore, the necessary minimum shape data of the inspection object is input in advance, and the positional deviation at the time of setting is the measurement result. It is sufficient to correct from the above.

  At this time, the TV camera 90 may have a camera capable of stereo imaging of a compound eye, or the surface shape of the inspection object 1 may be measured using a laser distance meter instead of the TV camera. May be.

  However, even if the TV camera 90 is a monocular camera, the amount of movement by the scanning mechanism 20 can be referred to. Therefore, if the three-dimensional distance is measured by photo measurement of images taken from a plurality of locations, it is combined with the position of the TV camera. The measurement value may be obtained, and the setting position of the scanning mechanism may be calibrated with the measurement data.

  By the way, when the surface of the inspection object 1 is plain and there are no visually distinctive points, the surface shape of the inspection object 1 cannot be measured from the image information even if it is photographed by the TV camera 90. Therefore, in this embodiment, two illumination devices 95 (1) and 95 (2) are used so that the entire surface of the pipe serving as the inspection object 1 is irradiated with a pattern having a predetermined pattern. In this state, the surface shape of the inspection object 1 is photographed by the TV camera 90.

  At this time, as a matter of course, a pattern may be drawn directly on the surface of the inspection object 1 by means of magic, paint, powder, etc., but the pattern is formed by the lighting devices 95 (1) and 95 (2). Since it is not necessary to process the inspection object 1 directly, it is easier to use.

  Here, the pattern at this time is a pattern in which a large number of points are scattered as shown in the figure. However, any pattern such as a plurality of straight lines or a mesh-like pattern in which a plurality of straight lines intersect is used. A pattern may be used.

It is a block diagram which shows 1st Embodiment of the automatic inspection system by this invention. It is explanatory drawing which shows an example of the defect which exists in a test target object. It is a block diagram which shows 2nd Embodiment of the automatic inspection system by this invention. It is explanatory drawing which shows an example of the probe in the 2nd Embodiment of this invention. FIG. 6 is a characteristic diagram of a signal level according to an embodiment of the present invention. It is explanatory drawing of the positional relationship of the probe and test target object in the 2nd Embodiment of this invention. It is explanatory drawing which shows an example of the positional relationship of the probe and test target object at the time of the defect detection by the 2nd Embodiment of this invention. It is explanatory drawing which shows an example of the defect detection operation | movement by the 2nd Embodiment of this invention. It is explanatory drawing which showed notionally the example of the detection result of the defect shape by the 2nd Embodiment of this invention. It is explanatory drawing which shows the 1st example of the probe used by embodiment of this invention. It is explanatory drawing which shows the 2nd example of the probe used by embodiment of this invention. It is a block diagram which shows 3rd Embodiment of the automatic inspection system by this invention. It is explanatory drawing which shows the 3rd example of the probe used by embodiment of this invention. It is explanatory drawing which shows the 4th example of the probe used by embodiment of this invention. It is explanatory drawing which shows the 5th example of the probe used by embodiment of this invention. It is a block diagram which shows 4th Embodiment of the automatic inspection system by this invention. It is a flowchart (the 1) which shows an example of the specific process flow of the scanning control data generation part in embodiment of this invention. It is a flowchart (the 2) which shows an example of the specific process flow of the scanning control data generation part in embodiment of this invention. It is a flowchart (the 3) which shows an example of the specific process flow of the scanning control data generation part in embodiment of this invention. It is a block diagram which shows 5th Embodiment of the automatic inspection system by this invention.

Explanation of symbols

1: Inspection object 2: Welded part 3: Defect 9: Contact medium 10: Probe (probe in the case of an ultrasonic probe)
10 Asm: Unit 10b in which a plurality of probes are arranged along the spherical surface 10b: Probe mounting base 10c: Probe attaching / detaching mechanism 10e: Probe signal changeover switch 20: Scanning mechanism 23: Probe direction rotating motor 25: Base carriage 26: Orbit 30 : Inspection data recording unit 35: Inspection data storage device (for inspection data storage)
40: Scanning control data generation units 40a to 40x: Processing of the scanning control data generation unit 42: Storage device (for storing initial scanning control data)
45: Storage device (for storing shape data for inspection)
50: Scanning mechanism control device 60: Display monitor 60C: Display control device 70: Storage device (for storing simulation results)
80: Storage device (for storing simulated defect data)
85: Simulator 90: TV camera 95 (1), 95 (2): Illuminating device 101: Shoe 102: Gimbal mechanism 104: Pressing spring 105: Cable from probe 900: Shape data generation unit

Claims (8)

In an automatic inspection system that automatically scans an inspection object with an inspection probe combined with a scanning mechanism, includes a means for processing the signal from the probe to detect the presence or absence of a defect, and acquires inspection data by the means,
A means for storing the inspection data obtained by scanning with the inspection probe together with the inspection data obtained by scanning previously is provided,
When the inspection object is automatically scanned by the inspection probe,
An automatic inspection system, wherein past inspection data is read and inspection conditions for the next scanning are automatically changed. The automatic inspection system according to claim 1,
The automatic inspection system, wherein the inspection probe has directivity, and at least one of the scanning mechanism and the inspection probe includes means for changing a directivity direction. In the automatic inspection system according to claim 1 or 2,
An automatic inspection system, wherein at least one of the scanning mechanism and the inspection probe itself is provided with means for changing characteristics of the inspection probe. The automatic inspection system according to claim 1,
An automatic inspection system, wherein the inspection probe is composed of an array type probe in which detection elements are two-dimensionally arranged. The automatic inspection system according to claim 1,
Means for detecting the presence or absence of the defect,
The data when the inspection object is scanned is compared with at least one of the data obtained by actually scanning the healthy inspection object under the same conditions and the data based on the simulation result, and the presence or absence of a defect is detected based on the degree of coincidence. An automatic inspection system characterized by that. The automatic inspection system according to claim 5,
Incorporate a defect model estimated from inspection data acquired in advance into a model that simulates when a healthy inspection object is scanned under the same conditions,
A means is provided for comparing data obtained by performing the simulation with data obtained when the inspection object is scanned, and determining whether or not the state of the defect has been sufficiently clarified by the degree of coincidence. An automatic inspection system characterized by that. In an automatic inspection system that automatically scans an inspection object with an inspection probe combined with a scanning mechanism, includes a means for processing the signal from the probe to detect the presence or absence of a defect, and acquires inspection data by the means,
Shape measuring means for measuring the shape of the inspection object and generating shape data;
An automatic inspection system comprising: means for automatically generating scan control data for the automatic scan based on the shape data. The automatic inspection system according to claim 7,
An automatic inspection system comprising means for adding a mark to the surface of the inspection object.

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